Apparatus for simultaneously pumping a plurality of liquids

Abstract

Apparatus for simultaneously pumping two or more different liquids to a spraying device has a pair of discrete diaphragm pumps for each liquid. The pumps of each pair are connected in parallel and operate alternatingly so that one pump delivers a metered quantity of liquid while the pumping chamber of the other pump receives a metered quantity of the same liquid and vice versa. The capacities of pumps of at least one pair are adjustable in a simultaneous operation, and all pumps are operated by a common prime mover.

I claim: 
     
       1. Apparatus for simultaneous delivery of metered quantities of a plurality of liquids, comprising a plurality of pump units, at least one for each liquid and each comprising a first and a second pump, the first and second pumps of each unit being arranged to operate alternatingly and being connected in parallel; a prime mover; operating means for connecting said pumps with said prime mover, including a reciprocable input member arranged to operate the first and second pumps of at least one of said units and including coaxial first and second components operatively connected to the first and second pumps of said at least one unit with freedom to perform idle strokes relative to the respective pumps; and adjusting means for simultaneously varying the capacity of pumps in said at least one unit to the same extent, including means for moving said components axially toward and away from each other to thereby vary the idle strokes and hence the capacity of pumps in said at least one unit. 
     
     
       2. The apparatus of claim 1, wherein said operating means further comprises an output member driven by said prime, mover, an input member for the pumps of another of said units, and means for transmitting motion from said output member to said input members. 
     
     
       3. The apparatus of claim 2, further comprising a housing for said units, said housing having a first section for said first pumps and a second section for said second pumps, said sections being spaced apart from one another and said motion transmitting means being disposed between said sections. 
     
     
       4. The apparatus of claim 3, wherein said output member is reciprocable and said sections comprise guide means for portions of said output member. 
     
     
       5. The apparatus of claim 3, wherein said first pumps are diaphragm pumps having a common diaphragm in said first section. 
     
     
       6. The apparatus of claim 3, wherein said second pumps are diaphragm pumps having a common diaphragm in said second section. 
     
     
       7. The apparatus of claim 3, wherein each of said sections defines a tank for a supply of a hydraulic fluid and means for admitting hydraulic fluid from the tanks to the pumps in the respective sections. 
     
     
       8. The apparatus of claim 1, further comprising a housing for said units, said housing including a first section for said first pumps and a second section for said second pumps, said sections being spaced apart from each other and said adjusting means being disposed between said sections and being accessible for adjustment of the capacities of first and second pumps in said one unit as a result of adjustment of idle strokes of said components 
     
     
       9. The apparatus of claim 1, wherein said moving means comprises right hand threads on one of said components, left-hand threads on the other of said components, and a sleeve having right-hand threads mating with the threads of said one component and left-hand threads mating with the threads of said other component, said sleeve being rotatable in two directions to thereby move said components toward or away from each other. 
     
     
       10. The apparatus of claim 1, wherein each of said components is provided with a plunger and each pump of said one unit comprises a cylinder defining a cylinder chamber for the respective plunger, and further comprising at least one tank containing a supply of hydraulic working fluid, said cylinders having openings which establish communication between said tank and the respective cylinder chambers in those axial positions of said plungers which are selected by said adjusting means. 
     
     
       11. The apparatus of claim 10, further comprising sealing means interposed between said plungers and the respective cylinders. 
     
     
       12. The apparatus of claim 1, wherein each pump of said one unit comprises a mobile pumping element arranged to draw liquid into and to expel the drawn liquid from the respective pump in response to reciprocation of said input member, and resilient restoring means for biasing said pumping elements in directions to draw liquid into the respective pumps, said components having means for mechanically moving the respective pumping elements against the opposition of said restoring means 
     
     
       13. The apparatus of claim 12, wherein said means for mechanically moving comprises dampers 
     
     
       14. The apparatus of claim 1, wherein at least one of said pumps is a diaphragm pump. 
     
     
       15. The apparatus of claim 10 wherein said components are arranged to seal the respective openings in response to completion of their idle strokes. 
     
     
       16. Apparatus for simultaneous delivery of metered quantities of a plurality of liquids, comprising a plurality of pump units, at least one for each liquid and each comprising a first and second pump, the first and second pumps of each unit being arranged to operate alternatingly and being connected in parallel; a housing for said units, said housing having a first section for said first pumps and a second section for said second pumps, said sections being spaced apart from one another; a prime mover, one of said sections having a side facing away from the other of said sections and said prime mover comprising a motor at said side of said one section; operating means for connecting said pumps with said prime mover, comprising an output member driven by said prime mover, an input member for the pumps of each unit, and means for transmitting motion from said output member to said input members, said motion transmitting means being disposed between said sections; and adjusting means for varying the capacity of pumps in at least one of said units. 
     
     
       17. Apparatus for simultaneous delivery of metered quantities of a plurality of liquids, comprising a plurality of pump units, at least one for each liquid and each comprising a first and a second pump, the first and second pumps of each unit being arranged to operate alternatingly and being connected in parallel; a prime mover; adjusting means for varying the capacity of pumps in at least one of said units; operating means for connecting said pumps with said prime mover, comprising a reciprocable input member arranged to operate the first and second pumps of said one unit and including coaxial first and second components operatively connected with the first and second pumps of said one unit, said adjusting means including means for moving said components axially toward and away from each other and each of said components being provided with a plunger, each pump of said one unit comprising a cylinder defining a cylinder chamber for the respective plunger and each of said components having limited freedom of axial movability relative to the respective plunger, said components and said plungers having confronting end faces which abut each other to shift the plungers in the respective cylinders during predetermined stages of movement of the respective components in a first direction, each pump of said one unit further comprising means for entraining the respective plunger during a predetermined first stage of movement of the corresponding component counter to said one direction; and at least one tank containing a supply of hydraulic working fluid, said cylinders having openings which establish communication between said tank and the respective cylinder chambers in those axial positions of said plungers which are selected by said adjusting means. 
     
     
       18. The apparatus of claim 17, further comprising a valve provided between each of said cylinder chambers and the respective openings, said valves being arranged to permit the flow of hydraulic fluid between said tank and said cylinder chambers when the confronting end faces of said components and the respective plungers are out of contact with one another during predetermined second stages of movement of the corresponding components counter to said one direction. 
     
     
       19. The apparatus of claim 17, wherein said entraining means comprise resilient elements interposed between said plungers and the respective components. 
     
     
       20. The apparatus of claim 17, further comprising stops arranged to arrest said plungers upon completion of first stages of movement of the respective components counter to said one direction. 
     
     
       21. Apparatus for simultaneous delivery of metered quantities of a plurality of liquids, comprising a plurality of pump units, at least one for each liquid and each comprising a first and a second pump, the first and second pumps of each unit being arranged to operate alternatingly and being connected in parallel; a housing for said units, said housing having a first section for said first pumps and a second section for said second pumps; a prime mover; operating means for connecting said pumps with said prime mover, including an axially reciprocable output member driven by said prime mover, axially reciprocable input members for the first and second pumps of said units, each of said input members comprising coaxial first and second components operatively connected to the respective first and second pumps with freedom to perform idle strokes relative to the respective pumps, and means for transmitting motion from said output member to said input members, said sections being spaced apart from one another and comprising guide means for said output member and said input members, said motion transmitting means being disposed between said sections and said input members being equidistant from said output member; and adjusting means for simultaneously varying the capacity of pumps in at least one of said units to the same extent, including means for moving the respective components axially toward and away from each other to thereby vary the idle strokes and hence the capacity of pumps in said at least one unit.